It is often desirable to treat large numbers of individuals or animals, referred to herein generally as subjects, with a substance, such as a medication or other material, with speed, efficiency, accuracy, and accurate maintenance of records. Often, the amount of the substance to be administered to the subject is based upon the weight of the subject. Generally, this requires weighing the subject and then calculating the amount of the substance based upon the subject's weight. After calculating the required amount, a delivery device, such as a syringe, is filled with the proper amount of the substance to be administered. Such a procedure can be time intensive, particularly when the number of subjects to be treated is great and the weight of the subjects vary.
As an example, the livestock industry requires routine vaccinating, medicating and/or treating of cattle or livestock. There are many diseases and illnesses contracted by livestock that need to be treated with various drugs and medications. Failure to properly treat the animals can result in significant losses to the rancher or feedlot or other party responsible for the livestock. Typically, the livestock is segregated into groups according to general size and weight. Often, the weight variation in a group of subjects is plus or minus 25% of the average weight of the group. Typically, the same amount of medication is administered to each of the subjects within a particular group. As a result, certain of the livestock are under-medicated while certain of the others are over-medicated. In both of these cases, unnecessary expense is incurred. In the case of the over-medicated livestock, the additional cost is from the unneeded, excessive amount of medication being administered while at the same time increasing tissue residue thereby increasing time until slaughter. In the case of the under-medicated livestock, the additional cost results from having to re-medicate the animal additional times, loss in performance, and significantly increased mortality. Furthermore, a decrease in market price is incurred for meat that cannot be sold as “grade” quality because the animal has a history of illness. These under-medication related problems result in an added expense per animal.
The size of the problem in the cattle feeding industry is substantial. In the United States alone, over 23.5 million head of cattle passed through the nation's feedlots in 1999. It is estimated that feedlots have a “sick rate” of approximately 25–30%. It is a common cow/calf procedure to wean and market calves simultaneously. Therefore, calves go from the farm or ranch to an order buyer's pens or an auction barn before ending up at the feedlot. Any livestock holding facility is a “cesspool” for pathogens that affect young cattle. Many of these calves have had only minimal, or sometimes no, vaccinations at home so they are serologically naive. Some of the calves have not received proper nutrition prior to weaning, resulting in immune incompetency. The added stress of weaning, hauling, and being “marketed” while at the same time being exposed to massive doses of pathogenic organisms can lead to resultant sickness and possible death loss. A large percentage of calves fall ill while moving through the feedlot process.
Both bacterial and viral pathogens are involved in feedlot diseases and are manifest as lameness, enteritis, and Bovine Respiratory Disease (BRD). The viral pathogens IBR, BVD types I and II, PI3, and BRSV, along with the bacterial pathogens Pasteurella haemolitica, Pasteurella multocida, Haemophilus somnus, and Corynebacterium spp., all play a part in BRD. Mycoplasma species can cause pneumonia and arthritis. By far, the greatest losses in life and production are from respiratory disease.
It is common upon arrival at the processing station for cattle to be vaccinated for viral respiratory disease (IBR, BVD, PI3, BRSV) and blackleg (7-way clostridium), implanted with a growth stimulant, and treated for internal and external parasites. In high stress situations, antibiotics are sometimes administered simultaneously with vaccinations. The signs of clinical BRD can range from just being off feed with no actual clinical signs to moribundity. Weakness and depression may be hardly noticeable at first. What starts out as rapid, shallow respiration soon becomes labored, open-mouth breathing. As the calf's condition worsens, so do the signs. Ocular and nasal discharges are usually present. Early intervention with appropriate therapy in this disease process is essential in controlling BRD. Processing and treating sick calves is a labor intensive and costly procedure with some antibiotics costing up to $1.00 per cubic centimeter (cc). Treating with the correct dosage for the exact weight is considered necessary. A system including a syringe that could be automatically filled with the appropriate antibiotic, in the correct volume as determined by weight, would save time, drugs, money, and lives.
U.S. Pat. No. 4,589,372 to Smith discloses a dispensing system for supplying and administering a metered dose of a material to a subject based upon the weight of the subject. The delivery system includes a scale for determining the weight of the subject and for generating a weight control signal to a microcomputer. An input keyboard is provided for enabling an operator to select various system initialization data and operating parameters. The microcomputer is responsive to the weight control signal and the weight conversion factor for generating a delivery control signal. A delivery unit is connected to a supply of the material and is responsive to the delivery control signal for supplying a predetermined amount of the material to the subject. The predetermined amount represents an amount which is a function of the weight of the subject and of the weight conversion factor. However, a problem exists in that the delivery of material is indescriminately automated. For example, if the predetermined amount of material to be delivered is 10 cc, the delivery unit will administer all 10 cc at one time. This is problematic because the user may not stop administering the material at 5 cc, reposition the hypodermic needle, and then administer the remaining 5 cc. Administering too much medication to one area of tissue could contaminate muscle tissue. Further, the injection process often requires quite a bit of “feel”, which comes from experience, as to which tissue layer the medicament is being administered. If the operator “feels” the needle point is not in the proper tissue layer, he may wish to stop the injection process and re-position the needle. This is not possible with syringes that are completely automated, such as the one disclosed in Smith. Additionally, some medicaments are lethal to humans, especially in the large dosage amounts administered to animals, e.g., 10 cc. An automated syringe, such as disclosed in Smith, is problematic in that an accidental injection into one of the operators would be potentially lethal.
It is desirable to have an automatic dosing syringe system that is highly accurate and dependable. It is also desirable that the automatic filling dosage system be capable of dispensing a variety of substances and be capable of operating in a wide range of ambient temperatures. It is desirable to have a dosage system with a syringe adapted to be automatically filled with the proper amount. It is also desirable to have an automatic filling dosage system and method capable of retrieving and updating the records for the subjects being treated. It is further desirable to have a dosage system that can be easily emptied, cleaned and disinfected without wastage of the medications. It is also desirable to have a manually operated syringe implemented with such a system.